Both 05 and 06-07 engines had a copper injector seat washer witch proved to be usless if not replaced every 45000km. Late 2006 the engine went euro4 and a water cooled EGR system was fitted but the ECU was not mapped for our stink diesel and this also caused carbon issues within the injector and throttle body. 2005 D4D euro3 system made the least amount of diesel konck but injectors had a major issue with carbon until they put a ceramic lining on the pin.